bis?
I'm not exactly sure what you're trying to say.
maybe if you say a lot? I don't think there is a 3 letter word that means again and again.
I've is a word that means I have. I'll is a word that means I will.
A 3-letter word that means "which person" is "who."
and
but
Ado.
Let
fan
hue
swiming
Law
Pad
Art